1. Field of the Invention
The present invention relates to a mobile terminal, a position search system, a position search method, and a program therefor, and more particularly, to a mobile terminal, a position search system, a position search method, and a program therefor, all of which are used when a third person conducts a position information search through a communication line.
2. Description of the Related Art
Methods using GPS (Global Positioning System) are known as conventional position-detecting capabilities. Because GPS Selective Availability (SA), that is, the intentional degradation of the GPS signals was removed in May 2000, the methods using GPS have been allowed to conduct position searches as positioning results with accuracies ranging from several meters to tens of meters. In position search services using base stations for cellular phones, it has also been considered how to improve the accuracy of position search.
Such position search services using positioning techniques include third-party search service that allows a user to retrieve or confirm the location of another person or third person in addition to the location of the user himself or herself. Using the third-party search service, if a position search is requested from a third person, authentication information such as a password will be generally verified so that only the search requests from the person or persons who were allowed by the user to conduct the searches (that is, who were informed by the user of the password) can be honored.
However, a malicious or ill-willed person may steal the password used for position search, or hide in a user's bag or the like a mobile terminal with position-detecting capability that is not the property of the user. In such a case, the above-mentioned position search service allows the malicious person to monitor the activities of the user, causing a problem of putting the user at risk of being a victim of a more serious crime such as an inversion of privacy or stalking.
In view of such a problem, the conventional position information search service limits its choice to either the option of denying the position search request from the third person according to the settings preset by the user regardless of the attributes of the position information requesting side, or the option of transmitting data as it is or after processed when transmitting current position information. Such service contents would wipe out close to half of its value as intended position search service. Here, the “attributes of the requesting side” are to tell family members or familiar others from a third person who might bear ill will toward the user.